1. Field of the Invention
The present invention relates to a high molecular weight polyether polyol, and more particularly to a high molecular weight polyoxyalkylene polyol and the method of preparing same.
2. Description of the Prior Art
The maximum molecular weight of base catalyzed oxide polymer is limited by the ratio of the rate of propagation to transfer. Therefore, only limited molecular weights of these products can be achieved by a direct oxyalkylation reaction. To obtain products of higher molecular weight other chemical methods are necessary.
One of these methods is by reaction with bis epoxides, as disclosed in U.S. Pat. No. 2,990,396. This patent discloses the reaction of polyoxyalkylene polyols with an organic polyepoxide compound. Wide ranges of products are obtained depending upon the ratio of polyepoxide to polyoxyalkylene polyol. Each time an interaction of an alcohol group of the polyoxyalkylene polyol with an epoxy group occurs, a secondary alcohol group is created which can react with epoxide to provide cross-linking. This is particularly the case when amount of polyepoxide is in a large excess over equivalent amounts, and the patent is directed primarily to these cross-linked products.